package main
import "fmt"
func main() {
	var str = "hello world"
	for i , value := range str {
		fmt.Printf("索引为：%d,具体的值为：%c \n",i,value)

}
    var num1 = 10
    var num2 = 20
    var result = sum1(num1, num2)
    fmt.Println(result)
}
